We are not going to make it easy for anyone to just not buy the book, Science and Human Origins, by Ann Gauger, Doug Axe, and Casey Luskin. And read for themselves why Ann Gauger thinks that Francisco Ayala is wrong in saying that the human race could not have had two first parents.

Before they hold forth.

But here are a couple of paragraphs:

The Challenge to the Challenge

Let’s step back and examine how Ayala’s analysis was done. His claims against a literal Adam and Eve are based on population genetics models for how gene frequencies change in populations over time, and how ancestral gene lineages tend to coalesce. The equations used to reconstruct these trees, and to calculate ancestral population sizes, depend on simplifications and assumptions to make the mathematics tractable, as I said before. These explicit assumptions include a constant background mutation rate over time, lack of selection for genetic change on
the DNA sequences being studied, random breeding among individuals, no migrations in or out of the breeding population, and a constant population size . If any of these assumptions turn out to be unrealistic, the results of a model may be seriously flawed.

There are also hidden assumptions buried in population genetics models, assumptions that rely upon the very thing they are meant to demonstrate. For example, tree-drawing algorithms assume that a tree of common descent exists. The population genetics equations also assume that random processes are the only causes of genetic change over time, an assumption drawn from naturalism. What if non-natural causes, or even unknown natural causes that do not act randomly, have intervened to produce genetic change?

It turns out that the particular DNA sequence from HLA-DRB1 that Ayala used in his analysis was guaranteed to give an overestimate, because he inadequately controlled for two of the above assumptions—the assumption that there is a lack of selection for genetic change on the DNA sequence being studied, and the assumption of a constant background mutation rate over time. (Pp. 111-12)

Um, what other possible origin is there? Unless “modern humans” arose at a dozen points at the same time (planted by Aliens?), there had to be a “1st Generation” in which 1 male and 1 female homo sapien found each other, mated, and produced viable offspring.

The step before this might involve a “one off” homo sapien mating with one of the earlier hominids to produce a second homo sapien child, but even the Darwinists can’t believe that new species appear in large numbers of individuals in the 1st generation. There can only be a new “species” when both parents of the new generation are also members of the new species.

To elaborate on your point, if evolution is true, then the sexes must have appeared at one point and there would be a male and a female. It seems unlikely that there would be a male and several females all in the first generation and of the same species.

But this discussion is made difficult by the vagueness of the term “human.” Does it include neanderthals?

Collin, to rebut Neodarwinian evolution you need to understand properly what it’s saying. According to population genetics, a new species doesn’t just mutate and arrive one day in an individual.

Imagine a group of, let’s say, 1000 Homo habilis gets cut off from the rest by migrating across a desert. Being a tribal group it happens to contain a higher proportion than average of, let’s say, red hair, small jaws, high IQ, voting Republican, tolerance to certain diseases etc.

Their side of the desert is rather different from native Habilisland, so the selection pressures are different and red hair makes good camouflage, Democrats get malaria and many of the original genes die out. Plus after a few thousand years some new mutations happen which didn’t exist in Habilisland. Time passes, and much later the tribe migrates back across the desert, to find these weird Homo habilis primitives with black hair, big teeth and a Democrat King. And they don’t even speak English, and their women smell of garlic. Our group became a new species without knowing it.

That (with poetic licence) is the ND picture of human origins without a first couple. In other words, the whole tribe became a new species. It would work biologically. The question is, does the evidence actually require that’s the way it happened? And it seems that’s what the book is addressing.

. . . .he inadequately controlled for two of the above assumptions—the assumption that there is a lack of selection for genetic change on the DNA sequence being studied, and the assumption of a constant background mutation rate over time.

Um, how could you possibly do this kind of work without assuming a constant background mutation rate without data suggesting otherwise?

I can’t see any other way to use homo sapien DNA to analyze the beginning and spread of “humans” than by admitting that you’re consistently talking about homo sapiens.

As far as we know, all hominids give birth to 1 baby at a time, with rare cases of twins or triplets. Even in the ancient historical period, the odds of 2 twins (let alone 3 triplets) surviving infancy were very low. So, it isn’t reasonable to assume that in a single generation 10 (for example) homo sapien children appeared from non-homo-sapien parents. The logical alternative, even assuming Evolution is true, is that after several false starts, 1 male and 1 female homo sapien found each other (even if born in different packs) and mated successfully.

Didn’t DNA analysis many years ago conclude that there was a “Mitochondrial Eve”? That is, all living homo sapiens on Earth are descendants of a single specific ancient human female. So the only question is whether, by chance, Eve had her pick of husbands. It makes more sense, statistically, that Eve could only find 1 male homo sapien during her short lifetime, even if there was another male homo sapien being raised by another band of hominids 50 miles away.

So there might in fact have been 100 Eves and 100 Adams, but 99 of them lived and died without finding another homo sapien mate. On the Neanderthal thing, the last I heard, the jury was still out on whether homo sapiens and Neanderthals could mate and produce fertile offspring. But at some specific, definable point in time, both our father and mother were pure homo sapiens, and all of their offspring continue to be h. sapiens.

I appreciate the review of the concept of genetic drift. I thought of it after I made my comment. What makes this issue difficult is the vaguness of the term “human.” Because there seems to be no hard separation between when the homo habilis becomes a human.

Excellent summary of the current ND view of speciation, John Garvey. And funny.

Collin, have you read the book?

Mahuna, the existence of mitochondrial Eve doesn’t indicate anything about how many females there were when she was alive, just that we all have inherited our mitochondria from her. Besides, Y chromosome Adam appeared roughly 70 years later, depending on what dates you use. So thinking of them as a first couple doesn’t work.

Ayala chose to analyze a segment of DNA known to be under strong selection, with an apparent mutation rate or gene conversion rate much higher than usual. When a neighboring intron was used instead (Bergstrom et al 1998 Nature Genetics 18, 237), the results changed significantly.

So in answer to your question, you choose a stretch of DNA not subject to selection (neutrally evolving), and with no evidence of high mutation rate or gene conversion.

Neanderthal-Heidelberg Distinction Blurs – June 2012
Excerpt: Chris Stringer is now claiming that the largest cache of Heidelberg Man fossils were really Neanderthals. The article reveals various forms of data manipulation to reformat the story of human evolution, such as recalculating the date of Sima fossils from Atapuerca, Spain (previously labeled Heidelberg) from 600,000 years old to 350,000 years old, so that they fit within the Neanderthal category.,, Cave paintings in from Spain have been re-dated as 40,800 years old, too old to be made by “modern” humans, and possibly made by Neanderthals. Live Science reported one anthropologist claiming “It would not be surprising if the Neanderthals were indeed Europe’s first cave artists.” That would have been very surprising not long ago. “Neanderthals have been portrayed as brutish, animalistic cavemen,” reporter Stephanie Pappas wrote, “but the archaeological evidence suggests they weren’t dummies. They buried their dead, made complex tools, and used decorative pigments.” So why not make art on the walls of their caves? Another anthropologist is convinced it is Neanderthal art.

Putting these two articles together, it appears the distinctions between Heidelberg Man, Neanderthal Man and Modern Man are flexible, being subject to the whims of certain living Homo sapiens who like to describe their disagreements and frequent changes of opinion as “a constructive scientific debate.”

Constructive for whom?

The real tragedy of these reversals is the momentum of falsified stories. There is a long time lag from the time old ideas are discarded to the time textbooks, museum displays and TV documentaries are replaced. Students are not told there is a “constructive scientific debate.” ,,,http://crev.info/2012/06/neand.....lberg-man/

“There are also hidden assumptions buried in population genetics models, assumptions that rely upon the very thing they are meant to demonstrate. For example, tree-drawing algorithms assume that a tree of common descent exists.”

Robust phylogenetic trees require, but do not assume, common descent. Tree-building algorithms rely on common descent to have produced patterns of nested hierarchical relationships because without these relationships existing, it would not be possible to build well-supported (i.e. high bootstrapping/posterior etc. support) trees.

The fact that such trees do exist and predominantly rely on effectively neutral changes in coding or non-coding sequences to have accumulated is strong evidence of common descent under population-genetic theory. Coalescent theory even allows us to make statistical predictions about lineage sorting – as recently misinterpreted by many hopeful creationists after the gorilla genome paper was published.

I am not aware of better alternative explanations for such phenomena than common descent.

“The population genetics equations also assume that random processes are the only causes of genetic change over time, an assumption drawn from naturalism. What if non-natural causes, or even unknown natural causes that do not act randomly, have intervened to produce genetic change?”

We can all idly speculate about what ifs. Lacking any evidence at all for them we do not put any weight into them as science, lest we generate Kiplingesque stories for the ridicule of the next Gould or Lewontin.

It may surprise some to find out that the evidence from population genetics itself, as intimidated as some may be by it, actually, when clearly understood, strongly refutes a Darwinian model for the origination of man: